From a Slice of Crystal to an IC Wafer

Our modern devices are powered by integrated circuits, tiny building blocks of the electronic world that begin, incredibly, as silicon dioxide – better known as sand. Enjoy a front row seat on the mind-blowing journey from sand to computer chip - through clean rooms, fabrication factories, and testing facilities. Hosted by industry insiders.

From a Slice of Crystal to an IC Wafer

Building an integrated circuit requires a series of manufacturing steps that introduce precise quantities of chemicals onto selected areas of the silicon wafer to form microscopic devices and interconnections. And each step must be performed in an ultra- clean environment to avoid contaminants.

Completed wafers are tested, sliced into individual chips, assembled into protective packages, and then tested again.

Wafers are placed in a high-temperature furnace to diffuse chemical dopants into the silicon in selective areas defined by “windows” etched through the oxide. The windows are defined by exposing light sensitive material coating the surface through the pattern printed on a photo mask.

The completed wafer is tested and cut into individual chips. The good devices are mounted into protective packages. Contact pads on the periphery of the IC are connected to external package leads with fine gold wires.

ICs in the 1960s typically had only 6 to 16 leads. With the aid of high quality microscopes, skilled operators were able to manipulate ultrasonic welders and attach tiny wires to contact pads and package leads.

The Manufacturing Process

A step-by-step process transforms a semiconductor crystal into an integrated circuit.

First, silicon wafers sawn from an ingot are polished to a mirror finish. After processing using photolithographic techniques—similar to printing processes—the completed wafer is tested, cut into individual chips, and assembled in robust packages for insertion into computer boards.

This is one of many special purpose machines needed for manufacturing ICs. It was used to scribe lines on the wafer in order to separate the chips before packaging. It won a Wescon Industrial Design award in 1965.